[django]合并多个查询结果集(queryset)并按字段排序

class Post(models.Model):
    #...

    created_at = models.DateTimeField(auto_now_add=True)
    reblog_from = models.ForeignKey('self', null=True, blank=True)

    #...


class Like(models.Model):
    #...

    post = models.ForeignKey(Post)
    created_at = models.DateTimeField(auto_now_add=True)

    #...

from itertools import chain
from operator import attrgetter

#...

post = Post.objects.get(pk=post_id)  # 获取博文
likes = likes = post.like_set.all()  # 获取喜爱信息
# likes = Like.objects.filter(post=post)
reblogs = Post.objects.filter(reblog_from=post)  # 获取转发信息

# 合并喜爱及转发信息，并按时间逆序排序
notes = sorted(chain(likes, reblogs), key=attrgetter('created_at'),
               reverse=True)

#...

>>> list(chain([1, 2, 3], 'abc'))
>>> [1, 2, 3, 'a', 'b', 'c']